POS0061 THE RISK OF LUNG CANCER IN RHEUMATOID ARTHRITIS AND IN RELATION TO AUTOANTIBODY POSITIVITY AND SMOKING
Authors: K. Chatzidionysiou, D. Di Giuseppe, J. Söderling, A. Catrina, J. Askling
Journal: Annals of the Rheumatic Diseases (2022)

<h3>Background</h3> Lung cancer is a common malignancy in rheumatoid arthritis (RA)<sup>1,2</sup>. Since smoking is a risk factor for both (seropositive) RA and lung cancer, it remains unclear whether RA, in itself, increases lung cancer risk. <h3>Objectives</h3> The aim of this study was to examine whether and to what extent the increased risk of lung cancer in RA may (or may not) be attributable to smoking, and to examine this association, both in terms of absolute and relative risks, specifically in relation to RA serostatus. <h3>Methods</h3> We performed a population-based cohort study of RA patients and individually matched general population reference individuals identified in Swedish registers and from the EIRA early RA study, prospectively followed for lung cancer occurrence 1995 through 2018. We calculated incidence rates and performed Cox regression to estimate hazard ratios (HR) including 95% confidence intervals (CI) of lung cancer, taking smoking and sero-status into account. <h3>Results</h3> Overall, we included 44,101 RA patients (590 incident lung cancers, 56 per 100,000), and 216,495 matched general population individuals (1,691 incident lung cancers, 33 per 100,000), corresponding to a crude HR (95% CI) of 1.76 (1.60-1.93). In subset analyses this increased risk remained after adjustment for smoking (HR=1.77, 95% CI 1.06-2.97). Compared to general population subjects who were never smokers, RA patients who were ever smokers had almost 7 times higher risk of lung cancer. Positive autoantibody status was associated with an at least doubled risk of lung cancer in ACPA positive patients (vs. ACPA negative patients) and double seropositive (vs. double seronegative) patients after adjusting for comorbidities and smoking (Table 1). The average absolute five-year risk of lung cancer counting from RA diagnosis was 1.3% in ever-smoking seropositive RA. At 20 years the risk was almost 3% in RA overall, and over 4% for patients who were ever smokers and had at least one autoantibody. <h3>Conclusion</h3> RA seropositivity is a strong and at least seemingly independent risk factor for lung cancer in RA. The absolute risks point to the potential for regular lung cancer screening, at least in seropositive RA. <h3>References</h3> [1]Simon TA, Thompson A, Gandhi KK, <i>et al.</i> Incidence of malignancy in adult patients with rheumatoid arthritis: A meta-analysis. <i>Arthritis Res Ther</i> Published Online First: 2015. [2]Khurana R, Wolf R, Berney S, <i>et al.</i> Risk of development of lung cancer is increased in patients with rheumatoid arthritis: A large case control study in US veterans. <i>J Rheumatol</i> 2008. <h3>Disclosure of Interests</h3> Katerina Chatzidionysiou Consultant of: consultancy fees from Eli Lilly, AbbVie and Pfizer, Daniela Di Giuseppe: None declared, Jonas Söderling: None declared, Anca Catrina: None declared, Johan Askling Grant/research support from: Karolinska Institutet has entered into agreements between Karolinska Institutet (JA as principal investigator) with AbbVie, BMS, MSD, Eli Lilly, Pfizer, Roche, Samsung Bioepis, Sanofi and UCB, mainly regarding safety monitoring of anti-rheumatic therapies